Abstract:
The aim of this study is to assess of the natural environmental radioactivity level and evaluation doses calculations.Total 114 Samples were collected contain soil، rock and some foodstuff from different locations around South and North Kordofan states. The radioactivity concentration of238U،232Th،40K and 137Cs have been determined using γ-rayspectrometry NaI(Tl) detector .moreover، the absorbed dose rates ate in air at a height of 1m from the ground was calculated using four sets of dose rate conversion factors and the corresponding annual effective dose were estimated،the average value of 238U،232Th،40K and 137Cs in thesoil samples from South Kordofan were found to be 22.83،25.11،284.31and 0.28Bq.k-1 respectively.
For South Kordofan. Activityconcentrations 238U،232Th،40K and 137Cs in the soil samples, were came out to be 22.08، 28.99 ،319.16 and 1.38Bqkg-1respectively. Predictive maps were constructed for both area for 238U،232Th،40K and absorbed dose using GIS program which showed a trend of increase to the Maintains area for soil Sample. Corresponding, for Foodstuff the average activity concentration of natural nuclides 238U،232Th and 40K fallout nuclide137Cs was 4.6، 4.4 and 326Bqkg-1respectively. Also activity concentrations of 238U،232Th and 40Kin rocks samples was 23.56، 29.57 and 330.58 Bqkg-1respectively.The obtained results were found to be less than the corresponding global values reported in the UNSCEAR publications for normal background areas.
The absorbed dose rate in air at a height of 1m from the ground was calculated using four sets of dose rate conversion factors and the corresponding annual effective dose was estimated. On the average, the values obtained were: 25.60، 25.26، 26.57 and 29.61nGy.h-1for soil samples North Kordofan،26.08، 28.05، 32.88 and 31.00nGy.h-1 for soil samples South Kordofan، 28.80، 28.42، 33.95and 33.34nGy.h-1 for rock samples، 5.53، 5.48،5.00 and 6.16 nGy.h-1 for Foodstuff samples، and annual effective dose were: 31.20، 30.99،32.60 and 41.72μSv.y-1for the soil samples North Kordofan،37.16، 34.42، 38.53and 39.81μSv.y-1for the soil samples South Kordofan38.19، 34.88،39.60 and 40.92μSv.y-1 for rock samples and 7.89، 6.72، 6.13 and 7.56 μSv.y-1for Foodstuff samples، respectively for DRCFs (MC، MCNP، GEANT and UNSEAR).These values lie within the areas very close worldwide range for high background radiation. The obtained data can be used in baseline data for any future studiesfor the establishment of radiation map for Sudan.
